The present invention relates to the field of medical technique for the location of tumors or the like, more particularly devices and probes adapted to be used on or introduced into the human body.
It has for its object a pre-operative location device for marked tissues, particularly by radioactive isotopes of superparamagnetic substances and/or by vital colorants, particularly for the detection and identification of lymphatic ganglia, as well as a process using said device.
The location of marked tissues with the help of isotopes emitting gamma radiation is known for the excision of cancerous tissues as well as for the identification of lymphatic ganglia called “hots”.
The auxiliary ganglia are for example excellent indicators of the prognosis and treatment to be used in the field of melanomas and of breast cancer.
However, the location of the so-called “sentinel” ganglion often gives rise to difficulties, particularly because of its proximity to the principal tumor.
Present devices of the nuclear type, although relatively sensitive, however do not permit a percentage of detection greater than 80%.
Another approach to the location of cancerous tissues consists in injecting a vital colorant which has the property of accumulating in the ganglia, then detecting the presence of regions strongly concentrated in colorant in the patient. This detection is at present carried out by visual observation of the resulting colored regions.
However, this second method has several drawbacks connected, on the one hand, to the nature itself of the colorants used (selectivity as to the tumor; retention time; troublesome indelible coloration of the visible tissues because of the necessary concentrations, particularly in cutaneous cancers, in breast cancers; cost . . . ) and, on the other hand, their use (determination of the injection point, of the paths of diffusion, precision of detection . . . )
As a result, there does not at present exist location apparatus which will be both very sensitive (percent of location greater than 95%), which has good spatial resolution, and which will be more capable of differentiating the primary radiations from the diffused radiations.